Artificial teeth



Patented Apr. 10, 1923.

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NILSEN BERCKA, OF BUENOS AIRES, ARGENTINA.

ARTIFICIAL TEETH.

Application filed September 2 1, 1921.

To all whom it may concern:

Be it known that I, NILsnN Bnnonn, a citizen of the Republic of Argentina, and resident of Buenos Aires, Argentina, South America, have invented certain new and useful Improvements in Artificial Teeth, of which the following is a specification.

The objects of this invention are inti mately related one withanother and prominent among them is the provision of design in which tooth fronts of varying sizes and differing conformation may be attached to a backing or bridge plate.

Another object is the means rovided for securing one or more artificia teeth to a backing plate having an attaching means to engage a channel formed at a slight angle to the rear face of the tooth, the channel being narrower at the open or gingival end of the tooth to produce a wedging action when engaging with the attaching means.

These and other objects are attained by the novel construction and arrangement of parts described in specification and shown by the drawing, forming a material part of this disclosure and in which Figures 1 and 2 are vertical central sectional views of tooth fronts of dissimilar sizes.

Figure 3 is a rear elevational View of a tooth front.

Figure 4 is a transverse sectional view taken on line 4-41 of Figure 3.

Figure 5 is a perspective view of a single tooth backing plate with tooth attaching means in place.

Figure 6 is a side elevational view of same.

Figure 7 is a perspective view of abacking or bridge plate showing a plurality of tooth attaching means positioned thereon.

Figure 8 is a rear elevational view of a tooth front with concaved back, shown as a modification of Fig. 3.

Referring to the figures in detail, the numeral 10 represents the front side of a tooth body and 11 its rear side. Interiorly of the body, at a slight angle to the rear side and centrally positioned with respect to the mesial and distal faces, is a parallel sided slot 12, the inner portion terminating in the widened, arcuately shaped bottom 13.

Referring to the Figures 1 and 2, it will be noted that the slots 12 and 13 terminate in the same plane equally distant from the incisal edge of the tooth regardless of the tooth size.

Serial No. 503,042.

It will also be apparent that the length of the slot upward from the line AA to the gingival end of the tooth varies in accordance with the size of the tooth, a distinct advantage over other known forms of detachable teeth, inasmuch as with the shrinking or recession of the gums a tooth originally fitted may be removed and a tooth of greater length betwe'enthe bottom of the slot and the gingival end substituted without loss of register at the incisal edges of the teeth.

Physical and mechanical difliculties of manufacture have been practically overcome Ilgy improved methods of moulding and ring.

Slotted backed teeth of usual form are frequently found with fire or shrinkage cracks extending from the interior square corners outwardly, causing great trouble and loss to the profession and the trade.

Referring to Figure l, the numeral 15 indicates fillets of considerable radius provided to overcome the liability of cracking at these vital points.

In the tooth described the conformation of back and gingival surfaces are perfect planes, a form permitting the widest latitude for grinding when necessary.

A modification of a tooth is shown in Fig. 8 and consists essentially of a tooth body containing slot elements 12 and 13, as previously described, a plane surface gingival end and a concaved back 16, both of which surfaces may be readily ground for proper fitting.

In attaching a removable tooth to a plate or bridge, pins and bars have been used that proved unsatisfactory, and to obviate the difiiculties the present invention includes a bar 20 having a semi-circular bead 21 integral with a central parallel sided rib 22, adapted to slidably engage a slot of corresponding shape formed in the tooth body.

This attaching bar may be made in rods of considerable length and cut off as required; one end is then squared and after being properly positioned on a single plate 25, as shown in Figure 5, or in plural arrangement as in Figure 7, when employed in bridge work, and secured to the plate by soldering or riveting.

In securing a tooth to a plate many expedients have been tried, but in the present device when the tooth body has been ground to gauge, so that the straight fiat walls of the recess 13 are slightly taperingrelatively to the rear-face 11, a tight joint is :produced, cross cuts or serrations 23 are formed on the rounded element 21 of the attaching bar 20,

5 providing space and anchorage for the small itziiiill beappar-ent that minor changes may begmade-in its construction, Without the exer- -cise of invention"or conflicting with the scope of theiclaim hereto appended.

.Having-thus described my invention, what I claim as new and desire to secure byLetters Patent, is:-

Tooth attaching means comprising in the-preferredembodiment of the invention,

the rear-surfaces ofthe teeth, the walls of the slots being thicker at the bottom than at the top, ribs extending outward from said plates, beads on said ribs adapted to engage in the slots of the teeth, and serrations on said heads adapted to contain cement to hold said teeth assembled thereon.

In testimony whereof I have signed any.

name tothis specification.

NJLLSEN BEROKA. 

